FEATURE ARTICLE: HOUSEHOLDS AND RENEWABLE ENERGY
While industry uses most of the energy in Australia, household energy consumption also has considerable implications for the environment, depending on the amount and type used. The main environmental issues associated with energy use include natural resource depletion, pollution and greenhouse gas emissions.

Household energy consumption is an important contributor to greenhouse gas emissions, particularly because of Australia's reliance on fossil fuels (e.g. coal, oil, gas) for electricity generation. While coal and gas are the lowest cost fuel sources for electricity in Australia, they have much higher greenhouse gas emissions than renewable energy sources (End note 1).The residential sector accounted for nearly one-tenth (9%) of total greenhouse gas emissions in 2007, mostly from energy use. Between 1990 and 2007, greenhouse gas emissions for this sector (excluding transport) grew by 28% ( End note 2 ).

Renewable energy sources, such as solar, hydropower, biomass and windpower, are naturally replenished and produce relatively few greenhouse gases. In 2007-08, about 5% of total primary energy came from renewable sources, including nearly three-quarters from biomass (72%), 15% from hydro-electricity and 7% from solar ( End note 3 ).

Households have a number of options for renewable energy sources, including installing small renewable generation units, for example, solar photovoltaic systems that convert sunlight directly into electricity, or more commonly, using wood or solar hot water systems. Another way is to sign up to GreenPower, whereby people can pay extra for electricity that is generated from renewable sources that feed into the electricity grid.

Changes in household energy use

Household energy consumption for cooking, heating/cooling, hot water and running appliances increased by 30% between 1990-91 and 2007-08 (End note 4). An increasing population, more appliances and IT equipment per household and bigger homes, have contributed to this growth.

The size and characteristics of people's homes affect household energy use and greenhouse gas emissions. For example, an increase in the amount of floor space will generally increase the amount of energy required to heat and cool a home. In 2008, more than one-third (37%) of separate houses had four or more bedrooms. More than three-quarters (77%) of all households used a heater and more than two-thirds (67%) used a cooler (graph 2.39).

Household use of space heaters and coolers is the major contributor (41%) to household energy use. Water heating (24%) and other appliances (13%) were also significant users of household energy. These top three energy uses produced a combined 64% of the household sector's greenhouse gas emissions in 2005 (End note 5).

Householders have increased their use of energy saving measures in their homes. In 2008, 59% of households had energy saving lighting installed (up from 33% in 2005) (graph 2.40); and energy star ratings were the main household consideration when replacing refrigerators, freezers, dishwashers and clothes dryers. Counteracting this, graph 2.39 shows more households now own coolers (66% in 2008 up from 35% in 1999) and dishwashers (45% in 2008 up from 30% in 1999) and other appliances, such as LCD and plasma televisions, the latter using almost three times the amount of energy compared to a standard television (End note 6).

2.40 Energy saving lights(a) in dwellings

Types of energy

Electricity

Electricity is the main energy source used in people's homes. In 2007-08, about half (49%) of the energy used by households was sourced from electricity. Household electricity consumption rose to 210 petajoules (PJ) in 2007-08, up 48% from 1990-91 (ABARE, 2009).

In March 2008, electricity was the primary source throughout Australia for household cooking (three-quarters of ovens used electricity and more than half (56%) of cooktops) and for hot water systems (46%). There has been a fall in the use of electricity for hot water systems between 2002 and 2008 from 61% to 46%.

Of those homes with heaters, electricity was the main source of energy for space heating (45%), followed by gas (41% for mains gas and LPG/bottled together) and wood (13%).

Natural gas

Natural gas is the second most common source of energy used in the home, used by more than six in ten households (61%) in 2008. In total, households used 137 PJ of natural gas in 2007-08, equivalent to almost a third (32%) of total household energy use (ABARE, 2009).

For almost one in three Australian households (31%), gas (mains or LPG/bottled) was the main source of energy for space heating and 37% used gas for hot water systems. In the main gas-producing states of Victoria and Western Australia, gas was used as an energy source in nine out of ten households (90% and 87% respectively, compared with six out of ten households nationally).

Used primarily as a source of heating, wood use by households has declined 26% in the last 10 years, from 82 PJ in 1997-98 to 60 PJ in 2007-08 (ABARE, 2009).

In 2008, 13% of Australian households used wood as a source of energy in the home. More than one-third (35%) of households in Tasmania used wood as an energy source, a decrease from more than half (52%) in 2002 (graph 2.41). Due to air pollution concerns, households have been encouraged to stop using wood for heating or to convert open fires to slow combustion fires, which are more energy efficient and produce less greenhouse emissions than open fires. Firewood collection can have a detrimental effect on Australia's native wildlife, as dead trees and fallen timber provide habitat for a diverse range of fauna including a number of threatened species (End note 7).

2.41 Wood, use in dwellings

Solar

A range of government grants and rebates have been made available to households in recent years to encourage people to use solar energy in the home. In 2008, 7% of households used solar energy to heat water, up from 4% of households in 2005. More than half of all households in the Northern Territory used solar energy to heat water (54%) - a much larger proportion than in Western Australia (21%) and no other state or territory exceeded 10% (graph 2.42).

GreenPower provides an option for people to pay a premium for electricity generated from renewable sources that is fed into the national power grid. GreenPower was first established in New South Wales in 1997 and since then has spread to other states and territories. By March 2009, just over 984,000 households were paying for GreenPower, up from 132,300 customers in March 2005 (End note 8).

There has also been an increase in the awareness of GreenPower products in the past decade. In 1999, less than one-fifth (19%) of households were aware of GreenPower. Nearly a decade later, this had risen to more than half (52%) of all households in 2008, including 5% who reported that they were already paying for GreenPower.

Households in the Australian Capital Territory had the highest rate of GreenPower awareness (71%, including 5% who were paying for GreenPower) while Western Australian households had the lowest awareness (39%) (graph 2.43).

2.43 GreenPower Awareness

Definitions

Biomass is plant material, vegetation or agricultural waste used as a fuel or energy source. Biomass can also be processed to produce liquid biofuels (biodiesel) or a gas biofuel (biogas).

Hydro-electric power is electricity produced from the energy of falling water using dams, turbines and generators.